好吧，在将此标记为重复之前，让我澄清一下自己。我正在阅读有关访客模式及其适用用途的信息。我偶然发现了这篇文章:WhenshouldIusetheVisitorDesignPattern?写下第一个答案的用户说:Nowwewanttoaddanewoperationtothehierarchy,namelywewanteachanimaltomakeitssound.Asfarasthehierarchyisthissimple,youcandoitwithstraightpolymorphism:...Butproceedinginthisway,eachtimeyouwanttoad